<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
	</body>
	
	<script>
		var x = 1;
		var y = 2;
		
		//这2个杯子中一共有多少升水  2 线上调试 
		
		var sum = x + y;
		
		console.log(sum);
		
	</script>
</html>
